The Expedition 22 crew members aboard the International Space Station were busy with a variety of science and maintenance activities Wednesday as they orbited the Earth.

Commander Jeff Williams continued working with the Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) experiment. SPHERES is designed to test control algorithms for spacecraft by performing autonomous rendezvous and docking maneuvers inside the station.

Expedition 22 Commander Jeff Williams performs a check of the Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) experiment in the Destiny laboratory of the International Space Station. Credit: NASA

He also worked with the Anomalous Long Term Effects in Astronauts’ Central Nervous System (ALTEA) experiment that measures details about the cosmic radiation passing through a crew member’s head. ALTEA provides in-depth information on the radiation experienced and its impact on the crew members’ nervous systems and visual perception.

Williams completed even more science experimentation as he spent time with the Advanced Plant EXperiments on Orbit – Cambium (APEX-Cambium) experiment. APEX-Cambium uses willow plants flown on the International Space Station to better understand the fundamental processes by which plants produce cellulose and lignin, the two main structural materials found in plant matter. Understanding the role of gravity in wood formation is expected to enable wiser management of forests for carbon sequestration as well as better utilization of trees for wood products.

Flight Engineer Maxim Suraev performed routine maintenance on the Russian segment of the station, replacing one of the power generation batteries in the Zvezda service module.

Suraev and Williams also took turns exercising on the COLBERT treadmill and the Advanced Resistive Exercise Device to counteract the effects of long-term exposure to weightlessness in space.

Meanwhile, the rest of the Expedition 22 crew back on Earth, Russian cosmonaut Oleg Kotov, NASA’s T.J. Creamer and Soichi Noguchi of the Japan Aerospace Exploration Agency, left the training center in Star City, Russia and arrived at the Baikonur Cosmodrome in Kazakhstan on Wednesday. They are scheduled for a Dec. 20 liftoff aboard the Soyuz TMA-17 spacecraft, docking with the space station two days later.